Film drier



R. SIMMON FILM DRIER Feb. 20, 1940.

I Filed Feb. '7, 1938 INVENTOR. RUDOLPH SIMMON ATTORNEY.

Patented Feb. 20, 1940 UNITED STATES PATENT OFFICE 1 Claim.

The present invention is directed to photo graphic films, and moreparticularly to an apparatus for drying the same after such films are developed.

Apparatus for drying films has been known for a considerable number ofyears and has been used. Various types of apparatus for such use havebeen proposed. Among such apparatus is type wherein there was provided aboxlike structure having within the same a motor-driven pump and havingin a separate ccupartment a series of incandescent lamps. Air from thepump or blower was caused to flow over the lamps to take up heattherein, and the air was then caused to pass into and through anotherboxlike structure containing photographic plates to be dried. Theseplates were held in suitable recesses in the bottom of the box and theair intended to pass thereover and to dry the same by direct contactwith said plates.

Such an apparatus was inefficient in that a series of lamps were usedfor heatin the resulting in an ineffective transfer of heat and causinga needless expenditure of energy. The drying compartment was very largecompared to the photographic plates therein so that a amount of air waswasted, again causing a need less expenditure of energy in circulatingthe air. Because of the manner of positioning the photographic plates,the drying was not uniform, resulting many times in defective plates.

Another type of apparatus previously used consisted in the provision ofsuitable chambers and an endless chain arrangement with numerouspulleys, sprockets, driving devices and the like. There was alsoprovided heating means for raising the temperature of the dryingchambers to the proper degree. The film in relatively long lengths wasintended to pass substantially continuously through the apparatus and tobe thus progressively dried. However, such an apparatus was quitecomplicated, expensive to build, and required expert operators in orderthat it might function satisfactorily. The arrangement was such that itcould not be adapted for the drying of short lengths of film such as arecommonly used in ordinary photographic work.

The present invention is intended to overcome the difficulties anddisadvantages of prior art structures, it being among the objectsthereof to provide a drying device for photographic films which shall besimple in construction and efilcient in operation.

It is a further object of the present invention to provide a film-dryingapparatus which is small, compact, easily set up, and capable ofmanipulation without expert operators.

It is a still further object of the present invention to provide anapparatus of. the character described in which the wet film may bereadily and 5 conveniently introduced into the apparatus without dangerof the wet emulsion being injured.

In practicing the present invention I provide a vertically placedelongated tube of relatively narrow cross section. Preferably, the tubeis circular and the film to be dried is hung in said tube from the topthereof. The diameter of, the tub is proportioned to the width of thefilm in such a manner that the film practically fills the space withinthe tube. However, the film is kept in a vertical position so that thereis no danger of contacting of the film with the sides of the tube,thereby eliminating the possibility of damage or injury to the emulsionthereon.

Said tube is placed upon a base consisting of 0 an enclosure in thebottom of which is a motordriven fan or blower and in the upper portionof which is a heating element. Air from the blower is caused to passover the heating element and into the bottom of the tube or casing,passing upwardly and outwardly through the tube thereof. The heated airthereby comes into direct contact with the film throughout its entirelength, and because of the restricted passageway, the operation is quiteefficient and the minimum amount of air for the drying operation isused. Because of a direct connection between the enclosure and thecasing, there is a minimum of resistance to the flow of air and thus anincreased efficiency of operation. The film is tained in a verticalposition during the drying operation, and for this reason there isnodanger of shrinkage or wrinkling of the film by reason of the drying.

Under some conditions it may not be necessary to provide heat for theair used in the drying operation. Therefore there is provided a pair ofswitches connected to the heating element and motor respectively. Saidswitches may be operated independently or simultaneously to place eitherthe blower into operation or to utilize both the blower and the heatingelement.

In the accompanying drawing constituting a part hereof and in which likereference characters indicate like parts;

Fig. l is a view in vertical cross section of an apparatus made inaccordance with the present invention, some of the elements thereofbeing shown diagrammatically; and

Fig. 2 is a transverse cross-sectional view of the apparatus takenalong-the line -2--2 of. Fig. l.

The apparatus described and claimed herein comprises a tube I of anysuitable material, usually of lightmetal but obviously may consist ofnon-metallic materials. Said tube is circular in cross section and is ofrather small diameter compared to its length.

The lower end of said tube or casing I is provided with a flange 2 whichis secured by suitable means to a similar flange 3 formed on the upperend of an enclosure 4. In the bottom of said enclosure is a blower 5operated by motor ii.

A source of electricity is attached to lead lines I which areoperatively connected to the motor 6 by suitable wires 9 having a switchIt interposed in said line. A heating element II in the upper part ofenclosure 4 has connected thereto wires I2 and I3, also in the circuitI, and provided with a switch I4 in the line.

The upper endI5, of the casing I is open to allow a free fiow of air,and a support I6 having film-holding members I1 is secured or placed onthe top of casing I. Support I6 is removably held on the top of tube I,whereby it may be removed,'the film clipped thereto'and then replaced.The ends of a strip of film are secured by clips I'I, and a roller orother device 20 is inserted at the loop 2I formed in the film when it ishung in a vertical position so that the major portion of the filmcomprises two parallel porvertical position and prevents contacting ofthe film with the sides of the casing I.

As will be seen more particularly in Fig.2, the width of the film issuch that the edges thereof almost touch the sides of casing I. It willfurther be noted that the emulsion side of the film,

although it faces the casing I, cannot come in contact with it so thatthere is no danger of the wet emulsion sticking to the casing and thuscausing blemishes in the dried film.

In the operation of the device, the memberIG holding the film invertical position as above described is placed as shown in Fig. 1Switches It] and I4 are closed, causing the blower 5 to operate and tocause a flow of air to pass upwardly through the enclosure 4. In passingover the heater II, the air is warmed to a desirable extent, and thewarm air then passes directly into the casing I, there being noobstructions to the flow of air nor any changes in direction of fiow.Thus there is a minimum of resistance to the flow of air. By reason ofthe positioning of the film and the presence of roller Zii, practicallyall of the air is caused to fiow into the spaces 22 and 23 between theface of the film and the sides of the casing. By thus restricting thepassage, the drying efiect is highly eificient and the amount of airnecessary for the operation is greatly reduced. Thus drying of the filmWill take place rapidly and eifectively with a minimum expenditure ofenergy.

Under some conditions, particularly when the humidity of the air isquite low and when the temperature of the air is sufliciently high,heating of the stream of air may be dispensed with. In such cases, inthe operation of the device, only the switch It is closed and switch I4is allowed to remain open.

Although I have described my invention setting forth a single embodimentthereof, it is apparent that various changes in the details ofconstruction of my device may be'made within the spirit of the presentinvention. For example, if it is desired to have a constant temperatureof air at all times, I may introduce into the circuit of heating elementII a thermostatic switch arrangement whereby the circuit of said heatingelement is automaticallly closed and opened in order to maintain asubstantially constant temperature of air flowing up through casing I.While I prefer to have the casing of circular cross section, variationsfrom a circular form may be made, as, for instance, the form may beelliptical, or any other geometric .iorm, which will restrict thepassage of air and at the same time eliminate the danger of the wet filmcontacting with the walls of the casing.

Various changes in the materials of construction, the form of thevarious elements, and the arrangement thereof may be readily devised.

These and other changes may be made in the details of construction of mydevice, and the invention is not to be limited except by the characterof the claim appended hereto.

What I claim is:

A film drier comprising a vertical elongated casing open at its lowerend approximately circular in cross section, means for introducing aflow of air into said end, an opening at the upper end of said casing, astationary holder for film at said upper end whereby said film is causedto hang in said casing, said holder having means for gripping both endsof a strip of film, a weight inserted in the loop at the lower end ofsaid film, the diameter of said casing being slightly larger than thewidth of said film to provide a restricted cross section of casing forminimizing the amount of air flowing therethrough and to prevent theface of said film from touching the wall of said casing.

RUDOLPH SIMMON.

